57156-80-6Relevant academic research and scientific papers
STEROIDS WITH THE β-CROTONATE (2-BUTENOATE) SIDE CHAIN
Cerny, Ivan,Pouzar, Vladimir,Drasar, Pavel,Turecek, Frantisek,Havel, Miroslav
, p. 128 - 140 (2007/10/02)
Ethyl (20E)-3β-methoxymethoxy-24-nor-5,20(22)-choladien-23-oate (Va) and analogous derivatives with 5α,5β and Δ5,14 steroid moiety (Vb, Vc and Vd, respectively) were prepared by Wittig-Horner reaction of the corresponding ketones IIa-IId with diethyl ethoxycarbonylmethylphosphonate.In this case the reaction affords exclusively the (E)-isomers, in contrast with the Peterson reaction with lithium salt of ethyl 2-(trimethylsilyl)acetate which gives a mixture of (E)- and (Z)-isomers at the Δ20(22) double bond.The structure of the products was confirmed by 1H NMR and 13C NMR spectroscopy. The crotonates Va-Vd were further converted into the 3-O-succinyl derivative VIIIa-VIIId.
